But while sunspot AR1520 may sound like a solar behemoth, it is actually a relatively modest sunspot example, and promises more sun storms to come, Dean Pesnell, project scientist for NASA's Solar Dynamics Observatory, told SPACE.com.

"It's certainly not done. It's only halfway across the face of the sun right now," Pesnell said from the Goddard center in Greenbelt, Md., which oversees the sun-watching SDO mission. "We'll be able to watch it from the Earth for at least another week."

Finally, solar protons accelerated by the blast are swarming around Earth. The radiation storm, in progress, ranks "S1" on NOAA space weather scales, which means it poses no serious threat to satellites or astronauts. This could change if the storm continues to intensify. Stay tuned.

Finally, solar protons accelerated by the blast are swarming around Earth. The radiation storm, in progress, ranks "S1" on NOAA space weather scales, which means it poses no serious threat to satellites or astronauts. This could change if the storm continues to intensify. Stay tuned.

NOAA and NASA’s predictions about the CME also differ on timing. Last night, NOAA was forecasting a 1 a.m. Saturday arrival of the CME while NASA projected a 6:20 a.m arrival. NOAA has since revised its estimate to 9:00 a.m. NASA tweaked its estimate to 5:17 a.m.

The differences in these predictions raise the question why two government agencies aren’t coordinating and issuing one clear, consistent forecast along with estimates of the uncertainty.

Consider this scenario: A hurricane is approaching the East Coast. What if one U.S. government agency predicted the storm would make landfall as a category 1 to maybe category 2 storm, at worst, while another agency forecast the storm to reach the category 2, 3 or even 4 level? Imagine the widespread confusion that would ensue. How would anyone know if and how to prepare?

NOAA and NASA’s predictions about the CME also differ on timing. Last night, NOAA was forecasting a 1 a.m. Saturday arrival of the CME while NASA projected a 6:20 a.m arrival. NOAA has since revised its estimate to 9:00 a.m. NASA tweaked its estimate to 5:17 a.m.

The differences in these predictions raise the question why two government agencies aren’t coordinating and issuing one clear, consistent forecast along with estimates of the uncertainty.

Consider this scenario: A hurricane is approaching the East Coast. What if one U.S. government agency predicted the storm would make landfall as a category 1 to maybe category 2 storm, at worst, while another agency forecast the storm to reach the category 2, 3 or even 4 level? Imagine the widespread confusion that would ensue. How would anyone know if and how to prepare?

NOAA and NASA’s predictions about the CME also differ on timing. Last night, NOAA was forecasting a 1 a.m. Saturday arrival of the CME while NASA projected a 6:20 a.m arrival. NOAA has since revised its estimate to 9:00 a.m. NASA tweaked its estimate to 5:17 a.m.

The differences in these predictions raise the question why two government agencies aren’t coordinating and issuing one clear, consistent forecast along with estimates of the uncertainty.

Consider this scenario: A hurricane is approaching the East Coast. What if one U.S. government agency predicted the storm would make landfall as a category 1 to maybe category 2 storm, at worst, while another agency forecast the storm to reach the category 2, 3 or even 4 level? Imagine the widespread confusion that would ensue. How would anyone know if and how to prepare?